Manually operable tool for installing blind anchor nuts

ABSTRACT

A MANUALLY OPERABLE TOOL FOR INSTALLING BLIND ANCHOR NUTS HAS A THREADED MANDREL WHICH CAN BE ROTATED BY A SHAFT HAVING AT ONE END A KEY ENGAGING A SOCKET ON THE MANDREL AND AT THE OTHER END A PROJECTING HANDLE. THE SHAFT IS BOTH ROTATABLE AND RECIPROCABLE, SO THAT THE KEY CAN BE DISENGAGED FROM THE MANDREL TO ALL ROTATION OF THE MANDREL IN SUCCESSIVE STEPS BY REPEATED ROTATION OF THE HANDLE THROUGH A SMALL ANGLE. THE MANDREL, THE KEY, AND AN ANVIL SURROUNDING THE MANDREL, MAY BE REMOVABLE AND INTERCHANGEABLE.

United States Patent i 13,ss7,271

Robert M. Rigot Granada Hills, Calif.

Mar. 19, 1969 Aerpat A. 6.. Zug. Switzerland Inventor Appl. No. FiledPatented Assignee MANUALLY OPERABLE TOOL FOR INSTALLING BLIND ANCHORNUTS 10 Claims, 11 Drawing Figs.

U.S. Cl 72/114, 81/55, 29/282 Int. Cl 821] 15/12, B2ld 39/04 Field ofSearch 81/55, 56,

53; 29/270, 282; 72/1 14, 391, (Inquired) [56] References Cited UNITEDSTATES PATENTS 2,562,419 7/1951 Ferris 72/391 3,462,988 8/1969Tudoretal. 72/114 Primary Examiner-James L. Jones, Jr. An0rneyl(emon,Palmer and Estabrook ABSTRACT: A manually operable tool for installingblind anchor nuts has a threaded mandrel which can be rotated by a vshaft having at one end a key engaging a socket on the mandrel and atthe other end a projecting handle. The shaft is both rotatable andreciprocable, so that the key can be disengaged from the mandrel toallow rotation of the mandrel in successive steps by repeated rotationof the handle through a small angle. The mandrel, the key, and an anvilsurrounding the mandrel, may be removable and interchangeable.

mi nnnnm mum!!! llorney MANUALLY OPERABLE TOOL FOR INSTALLING BLINDANCHOR NUTS The invention relates to a manually operable tool forinstalling blind anchor nuts. By f'blind anchor nut is meant a devicecomprising a tubular body portion and an internally threaded nutportion, the nut portion being capable of being pulled towards thetubular body portion to deform the body portion to tightly grip thewalls of a suitable aperture in which the body portion is inserted,thereby to install the anchor nut securely in the aperture. The anchornut is blind" in that its installation requires access to one side onlyof the aperture. One example of such a blind anchor nut is that widelysold under the Registered Trade Mark NUTSERT.

It is an object of the present invention to provide a manually operabletool for installing such blind anchor nuts which is simple inconstruction and economic in manufacture, and is also simple andfoolproof in use and unlikely to require maintenance or servicing inuse.

It is another object of the invention to provide such a tool which isreadily adaptable to fit anchor nuts of different sizes.

It is a further object of the invention to provide such a tool in whichconsiderable force can be applied to install the anchor nut, and whichcan be used to install nuts in relatively inaccessible positions.

Other objects of the invention will become apparent from the followingdescription, by way of example only, of one way of putting the inventioninto practice. The description refers to the accompanying drawings, inwhich:

FIG. 1 is a side elevation, partially in section, of the example handtool in a first operational configuration;

FIG. 2 is a similar view of the tool in a second operationalconfiguration;

FIG. 3 is a section on the line III-III of FIG. 2;

FIG. 4 is a section on the line IV-IV of FIG. 2;

FIG. 5 is an end elevation of the tool, taken in the direction of thearrow V in FIG. 2;

FIG. 6 is an end elevation of the tool, taken in the direction of thearrow VI in FIG. 2; and

FIGS. 7 to 11 illustrate on an enlarged scale, successive stages in theplacing of an anchor nut by the tool.

The manually operable tool of this example comprises a body member llhaving a bore 12 extending throughout its length. At one end of the borethere is an annular anvil 13 for engaging the body part of an anchornut. The anvil has a serrated outer end face 14 for frictionallyengaging the body of the anchor nut, the serrations being in the form ofradial V- section ribs and grooves. The annular anvil surrounds anaperture in the form of a bore 15 through it, which is aligned coaxiallywith the bore 12 in the body member. Formed integrally with the bodymember 11 is a grip in the form of a radially projecting handle 16, bymeans of which an operator can hold the body member and in particularprevent rotation thereof about the bore 12. The tool also has aninterchangeable mandrel I7 positioned in the bore 16 in the anvil. Themandrel has an externally threaded portion 18 extending outwardly of theanvil, and at its other end a hexagonal socket 19 facing into the bore12. The socket 19 is provided within an enlarged portion 21 at the innerend of the mandrel which prevents the mandrel from moving out throughthe bore 15 in the anvil. In the example, the mandrel I7 is provided bya hexagon cap socket screw, the enlarged portion 21 being the head ofthe screw. Washers may be provided between the screw head and the anvil13.

The tool further comprises a shaft 22 which is reciprocable androtatable within the bore 12 of the tool body. The shaft 22 is a slidingand rotating fit within an internal annular flange at the end of thebore 12 remote from the anvil 13. The shaft 22 is provided at its endnearer the anvil 13 with an interchangeable hexagon key 24 which willfit into and drivingly engage the socket 19 on the mandrel. The shaft 22is also provided with a handle 25 outside the body member of the tool.The handle 25 projects transversely of the shaft 22, so that it can beused by the operator for both rotating and reciprocating the shaft 22within the body member. The shaft is freely reciprocable between a firstposition (illustrated in FIG. I) in which the key 24 drivingly engagesin the socket 19 on the mandrel, so that rotation of the shaft 22 bymeans of the handle 25 causes rotation of the mandrel l7, and a secondposition (illustrated in FIG. 2) in which the key 24 is disengaged fromthe socket 19 on the mandrel, so that the shaft 22 may be rotatedwithout rotating the mandrel. When the shaft is in the second position,the screw mandrel 17 may move back through the anvil, but notsufficiently far to fall out ofthe bore 15 of the anvil.

In the tool of this example, the annular anvil I3 is interchangeable.The anvil is releasably retained in the body member by means of aretaining screw 26 engaged in a threaded hole 27 in the wall of the bore12, the screw 26 being screwed into engagement with the anvil. The anvilis provided with a radial bore 28 into which the end of the screw 26enters.

The interchangeable hexagon key 24 on the shaft 22 is received within arecess 29 in the end of the shaft. The shape of the socket, and of thepart of the key 24 which is received within the socket, are of suitablecomplementary noncircular shape to ensure positive rotation of the keyby the shaft. For example, the socket and the key body may both behexagonal, or may be of cross-sectional shape of a circle with one ormore flats in the side. The key 24 is releasably retained in the socket29 by means of a screw 31 engaged in a threaded hole 32 in the side wallof the socket 29, and engaging with the part of the key 24 within thesocket.

In the tool of this example, there is also provided releasable retainingmeans for releasably retaining the shaft 22 within the bore 12. Thisreleasable holding means is provided by an annular tapered shoulder 33inside the bore 12 of the tool body and facing towards that end of thebore which has the anvil 13. The shoulder 33 is provided by the innerend face of the flange 23. The shaft 22 is provided with a pair ofdetent members in the form of two small steel balls 34, 35, carriedwithin a transverse bore 36 in the shah. The balls 34, 35 are each urgedoutwardly by means of a helical coil spring 37 working between themwithin the bore 36. The metal surrounding each end of the bore 36 isstaked or paned over to prevent either ball emerging completely from thebore. When the shaft is in the first position (shown in FIG. I), theposition of the bore 36 and balls 34, 35 is well away from the annularshoulder 33 on the inner end of the flange 23. The spring 37 urges theballs 34, 35 to project outwardly from the shaft 22, but they do notproject sufficiently to contact the wall of the bore 12. However, whenthe shaft is moved back to the second position (shown in FIG. 2), theballs meet the tapered annular shoulder 33 on an inclined line ofcontact. The abutting of the balls 34, 35 against the shoulder 33restrains further movement of the shaft, thereby defining the secondposition of the shaft, and also acting as means to releasably retain theshaft within the bore. In order to withdraw the shaft 22 from the bore,it is necessary for the balls 34, 35 to be retracted into the bore 36against the urging of the spring 37, by the inclined face of theshoulder 33. The size and position of the balls 34, 35 and the slope ofthe annular shoulder 33, and the strength of the spring 37, are arrangedsuch that the operator can withdraw the shaft 22 from the bore by asharp tug on the handle 25, whilst holding the body member of the toolby means of the grip handle 16. This allows access to the key 24 forremoval and interchange thereof.

The operation of this tool will now be described, using as an example ofa fastener the one illustrated in FIGS. 7 to 11. This particularfastener is one commercially available under the Registered Trade Mark"NUTSERT". The fastener comprises a tubular body portion 51, having atone end a small head in the form of an outwardly extending flange 52. Atthe other end the tubular body portion joins the narrower end of aninternally threaded nut portion 53, which has a tapering exterior 54.The fastener is to be placed in a circular hole 55 in a metal sheet 56.The mandrel of the tool is chosen so that its threaded portion 18 mateswith the internal threading 50 on the nut 53. In use, the fastener isfirst inserted into the hole 55 with the head 52 towards the operator,until the head 52 abuts the sheet 56. With the shaft 22 of the tool inits first position (in which the key 24 engages the mandrel socket t9),the operator offers the threaded end E8 of the mandrel through the bodyportion 51 of the fastener and into the threaded nut portion, rotatingthe handle 25 continuously in a clockwise direction by turning it withone finger, whilst holding the body of the tool in his other hand bymeans of the grip handle 16. In this manner the threaded portion 18 ofthe mandrel is screwed fully into the nut portion of the fastener, untilthe serrated face 14 of the anvil I3 is drawn tightly against the head52 of the fastener (this position is illustrated in FIG. 9). Theserrations on the face 14 of the anvil engage with the head end of thefastener to prevent rotation thereof with respect to the body of thetool. In order to draw the nut portion of the fastener into the bodyportion, the operator continues to rotate the mandrel in a clockwisedirection. In order to apply the considerable torque required to themandrel, the operator holds the grip handle 16 in one hand and the shafthandle 25 in the other, and repeatedly carries out the following stepsin sequence:

1. with the shaft 22 in its first position (in which the key 24 engagesthe mandrel socket 19), forcefully turns the bandle 25 clockwise withrespect to the handle 16 through a small angle, thus screwing thefastener nut portion 53 towards the anvil face 14;

2. pulls on the handle 25, thus moving the shaft 22 from its firstposition to its second position (in which the key 24 is disengaged fromthe mandrel socket l9);

3. returns the handle 25 through the aforesaid small angle in ananticlockwise direction to substantially its original angular position;

4. pushes on the handle 25 to return it to its first position in whichthe key 24 engages in the mandrel socket 19(rotating the shaft slightly,if necessary, so that the hexagonal key 24 engages in the hexagonalsocket l9).

Thus if by repeated short amounts the nut portion 53 of the fastener isdrawn into the body portion 51, shearing the junction between the twoportions and eventually pulling the tapered nut portion completely intothe body portion, expanding the latter and securely wedging the fastenerin the hole (this position is illustrated in FIG. The operator then,with the shaft 22 in its first position with the key 24 engaging in themandrel socket 19, rotates the shaft anticlockwise to unscrew thethreaded mandrel from the nut portion of the fastener, leaving theplaced fastener in the sheet (as illustrated in FIG. 1 l

It is found that an operator can exert considerable torque on one handleof the tool with respect to the other, but only over a restricted rangeof angle between the two handles, due to the variation in relativeposition of the operators hands and arms as he rotates the handlesrelative to each other. The hand tool of this example enables the blindanchor nuts to be installed by repeated application of such a force,whilst at.the same time the construction and operation of the tool isextremely simple. It is intended that this tool should be used insituations where power operated tools cannot be used, i.e. for repairwork under field conditions, or as part of the repair tool kit of amotor vehicle.

Furthermore the tool allows easy and speedy interchange of the screwthreaded mandrel, together with interchange of the key 24 and anvil 13,which is necessary since a different diameter mandrel will certainlyrequire an anvil with a different diameter aperture and possibly adifferent size of driving key for the hexagonal socket. Thus the toolcan readily be adapted to place blind anchor nuts with different sizesand/or internal thread. The tool may, of source, be used to installblind anchor nuts of types other than that described in the foregoingexample.

Since the tool is operated by relative reciprocation of the two handles16 and 25 over a relatively small angle, it is possible to use the toolto install a blind anchor nut in situations which have relativelyrestricted access, for example near the corner point of three mutuallyperpendicular walls.

The invention may of course be put Into practlce otherwise an annularanvil at one end of the bore for engaging the body part of an anchornut, the annular anvil surrounding an aperture aligned with the bore; 1

a grip by means of which an operator can hold the body member to preventrotation thereof about the bore;

an interchangeable mandrel positioned in the aperture in the anvil, thesaid mandrel having an externally threaded portion extending outwardlyof the anvil and a socket facing into the bore;

a shaft rotatable and reciprocable in the bore of the body member whichshaft is provided at one end with key which will fit into the socket onthe mandrel in driving engagement therewith, the shaft also beingprovided with a handle outside the body member of the tool by means ofwhich the shaft can be both rotated and reciprocated with respect to thebody member;

the shaft being reciprocable between a first position in which the keyon the shaft engages in the socket on the mandrel thereby allowingrotation of the mandrel by means of the handle, and a second position inwhich the key disengages from the socket thereby allowing rotation ofthe handle without rotation of the mandrel.

2. A tool as claimed in claim 1, in which the said annular anvil isinterchangeable.

3. A tool as claimed in claim 2, including releasable retaining meansfor releasably retaining the said anvil on the body member ofthe tool.

4. A tool as claimed in claim 3, in which the releasable retaining meanscomprises a threaded hole in the body member, and a retaining screwscrewed into the hole and into engagement with the anvil.

5. A tool as claimed in claim 1, in which the said key at the said oneend of the shaft is interchangeable.

6. A tool as claimed in claim 5, in which the said one end of the shafthas a noncircular recess in which the key fits, and is provided withreleasable retaining means for releasably retaining the key in therecess.

7. A tool as claimed in claim 1, in which the said grip projectstransversely from the body member of the tool.

8. A tool as claimed in claim 1, in which the said body member of thetool and the said grip are formed integrally with each other.

9. A tool as claimed in claim 1, including means for releasablyretaining the said reciprocable shaft within the bore of the bodymember, said retaining means being releasable to permit withdrawal ofthe shaft from the bore to enable access to the key.

10. A tool as claimed in claim 9, in which the said releasable retainingmeans comprises an annular shoulder inside the bore of the body memberof the tool facing towards the said one end of the bore, at least onedetent member carried by the said reciprocable shaft, and spring meansurging the or each said detent member transversely outwardly of theshaft so it engages the said annular shouldcr along an inclined line ofcontact, the arrangement of the or each detent member and the annularshoulder, and the strength of the spring means, being such that anoperator can by a manual pull on the shaft with respect to the bodymember overcome the spring means and withdraw the shaft out of the bore.

